Control of particle size in the formation of polymer latices

Abstract A brief survey is given of the methods which can be used to produce polymer latices with a narrow size distribution. The factors which control both the particle size and the nature of the chemical groupings on the latex particle surface are discussed for latices prepared without the addition of an emulsifier. In particular, it is demonstrated experimentally that the ionic strength of the aqueous phase plays a major role in controlling particle size and that the free radicals produced by thermal decomposition of the initiator become incorporated as end‐groups on the polymer chains and hence form the surface groups on the particle. A theoretical explanation is given which indicates the reasons for the importance of ionic strength in controlling particle size.